A transmission component in a key structure of a traditional keyboard is a scissor transmission component, which comprises an inner scissor and an outer scissor. A connecting shaft is extendedly arranged along symmetrical sides on the inner scissor. A shaft hole is arranged at a corresponding position of the outer scissor. The inner scissor is coupled and matched with the outer scissor through the shaft hole. However, such transmission component has high production cost, and is difficult to control quality; moreover, it is hard to assemble, which requires a large amount of artificial assembly, and the production efficiency is low. Moreover, gaps may also be caused to shaft hole matching, so that the transmission structure is loosened.